Spark-plug.



A. SCHMIDT.

SPARK PLUG.

APPLICATION FILED MAR. I6. 1912.

Ll.. Patented oet. 5, 1915.

` narran srafras rarnu raro ALBERT SCHMIDT, OFFLINT, MICHIGAN, ASSIGNOR T0 CHAMPION IGNITION CMPAIT', 0F FLINT, MICHIGAN, A CORPORATION 0E MICHIGAN.

SPARK-PLUG.

Specicationvof Letters Patent.

Patented Oct. 5, MM5...

Application led 'March 16, 1912. Serial No. 684,115.

To all whom t may concern: v

Be it known that I, ALBERT SCHMIDT, a citizen of the Republic of France, residing at Flint, in the county of Genesee and State of Michigan, have invented certain new and useful Improvements in Spark-Plugs, of

which the following is a specification, ref er-- ence being had therein to the accompanying drawings.

The invention relates to spark plugs and has special reference to the construction of the electrode or sparking point which is grounded on the metallic case. Heretofore these electrodes have beenusually formed of wire of uniform cross section and which is easily bent out of place. Furthermore, as this wire is exposed to the heat of explosion and the heat conducting section'is. small the metal ils-frequently burned.

It is the object of the present invention to 'obtain a more substantial, rigidl and heat insulating electrode and to this end the invention consists in the construction as hereinafter set forth.

In the drawings, Figure l is a perspective view of the spark plug casing and electrode detached; Fig. 2 is a cross section through the case with the electrode secured thereto;

Fig. 3 isa similar view with the section at right angles to Fig. 2 and showing the electrode in elevation; Fig. 4 is a plan view; Fig. 5 is an enlarged section through the joint; Fig. 6 is a longitudinal secti on through the case before the completion `of the same; and Fig. 7 is a cross section of Fig. G after the completion of the same.

A is the metallic casing of the plug provided with the usual threaded portion for engaging the threaded apertures in the engine casing, B, B are lugs at the end of the casing A having a notch C therebetween, D

is lthe contact point or electrode which is formed of a sheet ,metal stamping .and 1s provided with a shank E for fitting into the Cri comparatively wide shank or base portion A gradually diminishing in width toward the point. This not only contributes a` greater y element of mechanical strength and rigidity .but also is favorable for conducting away the heat from the point of the electrode and dlstributing it into the body of the case.

The electrode is secured in position by first engaging the shank in the notch C and then riveting over the projecting lugs B and B on opposite sides of the notch as shown in Fig. 5. The electrode is then bent to extend over the end of the plug with its point in proper relation to the cooperating electrode.

For convenience in manufacture; the casing A is first formed with an integral disk H extending completely across the lower end thereof. This disk'is then struck out by a suitable die to remove all portions thereof with the lexception of the lugs B and B as shown in Fig. 7.

IVhat I claim as my invention is:

1. In a spark plug, the combination with the case, of spaced lugs on said case, an electrode formed of a tapermg sheet metal stamping having a shank engagmg said spaced lugs and secured thereto by the riveting over of the latter.

' In a spark'plug, the combination with the case, of an electrode formed of a tapering sheet of metal stamping having a shouldered shank portion, and spaced lugs on said case for receiving said shank and en- 'l gaging said shoulder, said lugs being riveted over the shank to secure the same.

In testimony whereof I aflix my signature in presence of two witnesses.

ALBERT SCHMIDT. IVitnesses MAGIBEL BRICKER, F. J. UTLEY. 

